Many scientific instruments are sensitive to vibrations from external sources, since such vibrations interfere with accurate measurements. An example of such an instrument is a scanning tunneling microscope which is used to study surfaces down to atomic accuracy. A fine metal tip is scanned just above a sample during an analysis, and any vibration distorts results.
The problem is addressed in several publications: a dissertation "Scanning Tunneling Microscopy for Surface Science" by Sang-il Park, G. L, No. 4130 (Stanford University 1987); and an article "Vibration Isolation for Scanning Tunneling Microscopy" by M. Okano, K. Kajimura, S. Wakiyama, F. Sakai, W. Mizutani, and M. Ono, J. Vac. Sci. Technol. A5(6), 3313-3320 (1987). Both publications disclose an outer stage suspended by one set of springs, and an inner stage suspended from the outer stage by another set of springs. Dampening of oscillations is effected with magnets. These arrangements require a significant amount of space, and eddy currents from magnets can interfere with the process of acquiring data using surface analysis techniques.
Therefore, an object of the invention is to provide a novel suspension system for isolating a platform from external vibrations. Another object is to provide such a system which utilizes a minimum of space. A further object is to provide a novel suspension system with non-magnetic dampening.